Through-Substrate Via (TSV) technology is being developed in the large scale integrated circuit package industry to facilitate the fabrication and design of a three-dimensional interconnect system. Using TSVs, connections can be made from an integrated circuit (IC) on the front-side (the side on which the IC components are fabricated) of a substrate die through the same die to the dies' back-side, where a connection can be made to another substrate die, interconnect structure, interposer, or IC package substrate. The efficient fabrication of such TSVs, which may number in the hundreds or thousands per die, is an important aspect of IC package cost, performance and reliability.